Fix descriptor semantics for initialized annotations
Sole Author: Patrick Ribbsaeter · Immutable Commit SHA: 8387bfded3736532e1b6c1c124264711ea0c50bc
Rust static type-inference fix in Meta Pyrefly preserving __get__ and __set__ descriptor protocol binding when class attributes carry both type annotations and descriptor initializers.
Commit 8387bfd
Merged Mainline
8387bfd
Immutable Git SHA
Rust
Compiler
52/52 CI Green
CI & Test Matrix
01 · Engineering problem
The failure mode
Meta Pyrefly classified an annotated instance attribute as a class-installed descriptor whenever its type implemented __get__, even when the attribute was explicitly initialized on self in __init__.
02 · Technical response
What changed
- 01Used DeclaredByAnnotation's initialized_in_recognized_method signal in Rust to skip descriptor synthesis for method-initialized instance fields.
- 02Added conformance tests for annotated + __init__-assigned fields while preserving class-descriptor behavior.
03 · Verified outcome
Evidence-backed result
- ✓Shipped upstream in meta/pyrefly at commit 8387bfded3736532e1b6c1c124264711ea0c50bc with zero mypy_primer regressions.
04 · Cryptographic Git record
Immutable source evidence
Independent open-source engineering authored solely by Patrick Ribbsaeter. Company and project names identify the public repository context only under nominative fair use. No employment, client, vendor, or partnership relationship is implied unless explicitly stated.